EVEREST II

April 4, 2011—Abbott Vascular (Santa Clara, CA) announced data from its EVEREST II (Endovascular Valve Edge-to-Edge Repair Study) study showing that patients with significant mitral regurgitation (MR) treated with the company's investigational percutaneous catheter–based MitraClip system continue to demonstrate the clinical benefits of initial treatment shown at 1 year out to 2 years, including improvements in heart function and reductions in symptoms.

Coprincipal investigator Ted Feldman, MD, presented the data. The EVEREST II investigators published the data simultaneously in The New England Journal of Medicine (2011;364:1395–1406). The EVEREST II investigators represent a variety of specialties including cardiac surgery and interventional cardiology, the company noted.

According to Abbott Vascular, the 2-year data from 279 patients from the EVEREST II trial demonstrated a clinical success rate of 51.7% for patients treated with the MitraClip device compared to a clinical success rate of 66.3% for surgery patients (P = .04) on an intention-to-treat basis. These results compare with the 1-year data, which demonstrated a clinical success rate of 55.2% for patients who received the MitraClip device and 73% for surgery patients (P = .0007). The clinical success rate is defined as freedom from death, surgery for valve dysfunction, and moderate to severe MR (3+ or 4+).

Data from the EVEREST II study showed other positive benefits on an intention-to-treat basis.

At 30 days, the MitraClip system demonstrated superior safety compared to surgery, with 15% of MitraClip patients and 47.9% of surgery patients experiencing a major adverse event, defined as a composite of 12 prespecified adverse events (P < .001).

At 1 and 2 years, both the MitraClip and surgery groups experienced a significant reduction (P < .05) in the end systolic and end diastolic volume of the left ventricle heart chamber compared to baseline, indicating an improvement in heart function. In both groups, the decrease in end diastolic volume that was observed between baseline and 1 year continued to decrease between years 1 and 2.

Both the MitraClip device and surgery experienced a statistically significant reduction in New York Heart Association (NYHA) Functional Class symptoms at 1 year that was sustained through 2 years.

At 2 years, 78% of patients randomized to the MitraClip device were free from surgery.

Abbott Vascular stated that longer-term follow-up of patients in EVEREST II is planned and will provide additional data to better understand the benefits of the MitraClip device.

In The New England Journal of Medicine, the EVEREST II investigators stated that “although percutaneous repair was less effective at reducing mitral regurgitation than surgery before hospital discharge, at 12 and 24 months the rates of reduction in mitral regurgitation were similar, and percutaneous treatment was associated with increased safety, improved left ventricular dimensions, and clinical improvements in NYHA class and quality of life.”

The MitraClip system received CE Mark in March 2008 and is commercially available in Europe, Turkey, Israel, and Australia. The first-in-man clinical trial of the MitraClip system has been conducted in the United States, where it is an investigational device currently under review for approval by the US Food and Drug Administration, advised Abbott Vascular.